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SURFACE WATER HYDROLOGY The CEC site drainage plan and the associated structures are discussed in Appendix K of the Permit, and can also be found in Technical Revision #28 (2/95), "Drainage Control Plan II". During reclamation, the diversion ditches, drainage ditches, and drainage swales that have been, and continue to be maintained along the roads, and around the north and east sides of the CEC property. These features serve to convey any surface water runoff to Sediment Pond 2. The present drainage facilities, as well as existing site topographic features, are shown on the Existing Surface Features and Utilities Map (see page 134). Certain surface water control features have been designated as permanent facilities (by Permit revision, and at the direction of CDMG and others). These features will remain following the completion of all site reclamation activities. The permanent facilities include: • Sediment Pond #2 • The East and the West Perimeter Ditches • The Dugout Pond The permanent drainage features are identified on the Reclamation Contour and Drainage Plan Map (see page 135). With the exception of Sediment Pond 2 and the Dugout Pond, all previously existing man-made temporary pond sites have been closed, and subsequently deleted from the drainage control mapping and monitoring requirement. This action is considered appropriate because: 1) the sedimentation infill of Sediment Pond 2 has been virtually non-existent after more than fifteen years of continuous use, 2) Sediment Pond 2 has not had significant amounts of water stored in it for more than brief periods (except during the unusual and prolonged periods of excess precipitation in 1995 and 1999), and 3) even considering those unusual events of 1995 and 1999, to date there has not been an observed discharge from Sediment Pond 2. CEC also implemented a dewatering scheme for Sediment Pond 2 in 1997, in conjunction with the preparation of a, "Spill Prevention, Control and Countermeasures Plan" for the site. This "Plan" was reviewed and updated in 2003. As conditions warrant, CEC personnel will pump the excess stormwater runoff accumulated in Sediment Pond 2 back to the Dugout Pond which is located about 700 feet slightly upgradient and to the south-southeast on the CEC property. The Dugout Pond has an available storage capacity exceeding the total contributing • runoff volume associated with a 100-year, 24-hour design storm event (refer to "Technical Revision Drainage Control Plan II," dated January, 1995). A series of AHR-2005 -8 8-